SARANDA, Albania (AP) — Albanian police said Wednesday they arrested five opposition supporters for allegedly damaging ballot boxes and documents to prevent upcoming municipal elections, while the government proposed punishing people convicted of election interference by prohibiting them to leave the country.

The opposition is boycotting the local elections planned for June 30 and has threatened to disrupt them. Supporters of opposition parties and police clashed Wednesday in about half a dozen municipalities. Albanian media outlets reported that at least five civilians and officers were injured.

Police accused the people arrested of physically attacking state police officers while storming election offices in the northern Albania city of Shkodra a day earlier.

Albania’s Socialist-led government insists the voting will go ahead as scheduled. Interior Minister Sander Lleshaj said police would arrest “anyone violating the law and will deposit enough evidence for their punishment.”

Prime Minister Edi Rama said the government drafted a law that would prohibit citizens convicted of hampering an election process to leave Albania for five to 10 years.

The Organization for Security and Cooperation in Europe condemned the election-related conflicts, saying instigators and perpetrators of violence should be held legally accountable.

“Any attempt to derail a democratic process through violent actions infringes the law, stalls the progress of the country and stains its international reputation,” the OSCE office in Albania said in a statement.

In another election development, the leader of the main opposition Democratic Party, Lulzim Basha, said prosecutors have provided no evidence for money-laundering and improper campaign spending two years ago.

Basha and two other party officials have been accused of illegally spending about $650,000 money linked to Russia through a lobbyist and a foreign company with offices in Scotland.